Intro to the Maintenance P-F Curve

An introduction to the fundamental concept of the P-F Curve where we can identify the point of functional failure (what the user wants it to do) and proactively find it in the act of failing prior to that point. The goal is to have enough advance notice that we can effectively plan and schedule the repair, get the materials and execute the repair prior to failure.

Transcript

Hello. I'm Jeff Shiver, Managing Principal of People and Processes. Today I want to discuss the P-F curve.

When we talk about the P-F curve, what we're basically talking about is establishing a level where the user has a want. Let's consider that we have a pump, and that pump, the process requires 100 GPM. As an engineer, we bought the pump, and we bought it at 150 GPM to make sure that we could satisfy that want. I'm going to label the 100 GPM as the want, and I'm going to label the 150 GPM as the can, or the capability of the pump.

Now, I hope you would agree that over time, say, if we take a particular component, maybe the impeller of that pump, it's going to wear. Maybe it wears until we've reached total failure. That's obviously not where we need to be.

Once we reach this point, we've actually functionally failed, which is very different than total failure. We functionally failed at this point, so what I'll do is draw a line, and this is what we call the failure. Now, at some point, we can actually detect this in the act of failing. Maybe that's at 105, we set that up. Maybe from an operator inspection where they're viewing a flow meter or they're looking at the output of a valve or something like that. At this particular point, we now have the potential for failure.

So we have a window called the P-F interval. What's important there is that we have a wide enough window that we can proactively plan, schedule, get the parts, and complete the repair before we ever reach this functional failure point. That's the goal of the P-F curve.

Again we're falling off, the impeller's wearing over time, our flow's dropping down, but at some point, we'll reach the functional failure. Before that, we actually look and say, "Where is it that we can find this in the act of failing?" That's our potential. We try to make sure that we maximize the life of this component but at the same time we have a big enough window that we can proactively plan and schedule the repair before we functionally fail.

That's the whole concept around the P-F curve.

Hope you enjoyed the tip. I'm Jeff Shiver, managing principal of People and Processes. Have a great day.